:root {
    /* Modern Color Palette */
    --color-forest: #1a472a;
    --color-forest-light: #2d5e40;
    --color-sea: #0f2b3e;
    --color-sea-light: #1a3c52;
    --color-moss: #88a090;
    --color-sand: #e8e6df;

    --color-bg-light: #f0f2f5;
    --color-bg-dark: #121212;

    --color-text-light: #1a1a1a;
    --color-text-dark: #e0e0e0;

    --color-white: #ffffff;
    --color-glass-light: rgba(255, 255, 255, 0.8);
    --color-glass-dark: rgba(15, 43, 62, 0.8);

    --color-error: #ff6b6b;

    /* Fonts */
    --font-main: 'Outfit', sans-serif;

    /* Spacing & Radius */
    --spacing-xs: 4px;
    --spacing-sm: 8px;
    --spacing-md: 16px;
    --spacing-lg: 24px;
    --spacing-xl: 32px;

    --radius-sm: 12px;
    --radius-md: 20px;
    --radius-lg: 30px;
    --radius-full: 9999px;

    /* Shadows */
    --shadow-sm: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
    --shadow-glow: 0 0 20px rgba(136, 160, 144, 0.3);

    /* Transitions */
    --transition-fast: 0.2s ease;
    --transition-normal: 0.3s ease;
}

/* Reset & Base */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: var(--font-main);
    background-color: var(--color-bg-light);
    color: var(--color-text-light);
    transition: background-color var(--transition-normal), color var(--transition-normal);
    height: 100vh;
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

body.dark-mode {
    background-color: var(--color-bg-dark);
    color: var(--color-text-dark);
}

/* Glassmorphism Utilities */
.glass {
    background: var(--color-glass-light);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid rgba(255, 255, 255, 0.3);
}

body.dark-mode .glass {
    background: var(--color-glass-dark);
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}

.glass-panel {
    background: rgba(255, 255, 255, 0.9);
    backdrop-filter: blur(16px);
    border: 1px solid rgba(255, 255, 255, 0.5);
    box-shadow: var(--shadow-lg);
}

body.dark-mode .glass-panel {
    background: rgba(30, 41, 59, 0.9);
    border: 1px solid rgba(255, 255, 255, 0.1);
}

/* Navigation */
.top-nav {
    padding: var(--spacing-md) var(--spacing-xl);
    display: flex;
    justify-content: space-between;
    align-items: center;
    z-index: 100;
}

.nav-brand {
    font-size: 1.5rem;
    font-weight: 600;
    background: linear-gradient(135deg, var(--color-forest), var(--color-moss));
    background-clip: text;
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

body.dark-mode .nav-brand {
    background: linear-gradient(135deg, var(--color-moss), #fff);
    background-clip: text;
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.nav-tabs {
    display: flex;
    gap: var(--spacing-sm);
    background: rgba(0, 0, 0, 0.05);
    padding: 4px;
    border-radius: var(--radius-full);
}

body.dark-mode .nav-tabs {
    background: rgba(255, 255, 255, 0.05);
}

.nav-btn {
    background: none;
    border: none;
    color: inherit;
    font-family: inherit;
    font-weight: 500;
    padding: 8px 20px;
    border-radius: var(--radius-full);
    cursor: pointer;
    transition: var(--transition-fast);
    opacity: 0.7;
}

.nav-btn:hover {
    opacity: 1;
}

.nav-btn.active {
    background-color: var(--color-white);
    color: var(--color-forest);
    box-shadow: var(--shadow-sm);
    opacity: 1;
}

body.dark-mode .nav-btn.active {
    background-color: var(--color-forest);
    color: var(--color-white);
}

/* Controls */
.icon-btn {
    background: rgba(0, 0, 0, 0.05);
    border: none;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: var(--transition-fast);
    font-size: 1.2rem;
}

.icon-btn:hover {
    background: rgba(0, 0, 0, 0.1);
    transform: rotate(15deg);
}

body.dark-mode .icon-btn {
    background: rgba(255, 255, 255, 0.1);
    color: var(--color-white);
}

.text-btn {
    background: none;
    border: 2px solid currentColor;
    padding: 6px 16px;
    border-radius: var(--radius-full);
    font-weight: 600;
    cursor: pointer;
    color: inherit;
    opacity: 0.8;
    transition: var(--transition-fast);
}

.text-btn:hover {
    opacity: 1;
    background: rgba(0, 0, 0, 0.05);
}

/* Main Content */
#main-content {
    flex: 1;
    position: relative;
    overflow: hidden;
}

.tab-content {
    display: none;
    height: 100%;
    width: 100%;
    animation: fadeIn 0.4s ease;
}

.tab-content.active {
    display: block;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Tree View */
#tree-container {
    width: 100%;
    height: 100%;
    position: relative;
    overflow: auto;
    background-image:
        radial-gradient(circle at 10% 20%, rgba(26, 71, 42, 0.05) 0%, transparent 20%),
        radial-gradient(circle at 90% 80%, rgba(136, 160, 144, 0.1) 0%, transparent 20%);
}

#relationship-lines {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: 0;
}

/* Modern Cards */
.family-card {
    position: absolute;
    background: var(--color-white);
    padding: var(--spacing-md);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-md);
    width: 220px;
    text-align: center;
    cursor: pointer;
    z-index: 1;
    transition: all var(--transition-fast);
    border: 1px solid rgba(0, 0, 0, 0.05);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 4px;
}

body.dark-mode .family-card {
    background: var(--color-sea-light);
    border: 1px solid rgba(255, 255, 255, 0.05);
    color: var(--color-white);
}

.family-card:hover {
    transform: translateY(-4px) scale(1.02);
    box-shadow: var(--shadow-lg);
    border-color: var(--color-moss);
}

.card-avatar {
    width: 48px;
    height: 48px;
    border-radius: 50%;
    background: var(--color-bg-light);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    margin-bottom: var(--spacing-sm);
    color: var(--color-forest);
}

body.dark-mode .card-avatar {
    background: rgba(255, 255, 255, 0.1);
    color: var(--color-moss);
}

.card-name {
    font-weight: 600;
    font-size: 1.1rem;
}

.card-dates {
    font-size: 0.85rem;
    opacity: 0.7;
    background: rgba(0, 0, 0, 0.05);
    padding: 2px 8px;
    border-radius: var(--radius-full);
    margin-top: 4px;
}

body.dark-mode .card-dates {
    background: rgba(255, 255, 255, 0.1);
}

/* FAB */
.fab {
    position: absolute;
    bottom: 40px;
    right: 40px;
    width: 64px;
    height: 64px;
    border-radius: 24px;
    /* Squircle */
    background: var(--color-forest);
    color: var(--color-white);
    border: none;
    font-size: 32px;
    box-shadow: var(--shadow-lg);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition-normal);
    z-index: 10;
}

.fab:hover {
    transform: scale(1.1) rotate(90deg);
    background: var(--color-forest-light);
    box-shadow: var(--shadow-glow);
}

/* Modals */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.4);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 1000;
    backdrop-filter: blur(8px);
    opacity: 0;
    pointer-events: none;
    transition: opacity var(--transition-normal);
}


.close-modal {
    position: absolute;
    top: var(--spacing-md);
    right: var(--spacing-md);
    width: 32px;
    height: 32px;
    border-radius: 50%;
    background: rgba(0, 0, 0, 0.05);
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: var(--transition-fast);
}

.close-modal:hover {
    background: rgba(0, 0, 0, 0.1);
    transform: rotate(90deg);
}

/* Forms */
h2 {
    margin-bottom: var(--spacing-lg);
    font-weight: 600;
}

.form-group {
    margin-bottom: var(--spacing-md);
}

.form-row {
    display: flex;
    gap: var(--spacing-md);
}

.form-row .form-group {
    flex: 1;
}

.form-section {
    background: rgba(0, 0, 0, 0.03);
    padding: var(--spacing-md);
    border-radius: var(--radius-md);
    margin-bottom: var(--spacing-md);
}

body.dark-mode .form-section {
    background: rgba(255, 255, 255, 0.03);
}

.form-section h3 {
    font-size: 0.9rem;
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-bottom: var(--spacing-md);
    opacity: 0.7;
}

label {
    display: block;
    margin-bottom: 6px;
    font-weight: 500;
    font-size: 0.9rem;
    opacity: 0.9;
}

input,
textarea,
select {
    width: 100%;
    padding: 12px 16px;
    border: 2px solid transparent;
    background: rgba(0, 0, 0, 0.05);
    border-radius: var(--radius-sm);
    font-family: inherit;
    font-size: 1rem;
    transition: var(--transition-fast);
    color: inherit;
}

body.dark-mode input,
body.dark-mode textarea,
body.dark-mode select {
    background: rgba(255, 255, 255, 0.05);
}

input:focus,
textarea:focus,
select:focus {
    outline: none;
    background: var(--color-white);
    border-color: var(--color-forest);
    box-shadow: 0 0 0 4px rgba(26, 71, 42, 0.1);
}

body.dark-mode input:focus,
body.dark-mode textarea:focus,
body.dark-mode select:focus {
    background: rgba(255, 255, 255, 0.1);
    border-color: var(--color-moss);
}

/* Radio Group */
.radio-group {
    display: flex;
    gap: var(--spacing-md);
}

.radio-label {
    display: flex;
    align-items: center;
    gap: 8px;
    cursor: pointer;
    background: rgba(0, 0, 0, 0.05);
    padding: 8px 16px;
    border-radius: var(--radius-full);
    transition: var(--transition-fast);
}

body.dark-mode .radio-label {
    background: rgba(255, 255, 255, 0.05);
}

.radio-label:hover {
    background: rgba(0, 0, 0, 0.1);
}

input[type="radio"] {
    width: auto;
    margin: 0;
}

.primary-btn {
    background: linear-gradient(135deg, var(--color-forest), var(--color-forest-light));
    color: var(--color-white);
    border: none;
    padding: 14px;
    border-radius: var(--radius-full);
    cursor: pointer;
    width: 100%;
    font-size: 1rem;
    font-weight: 600;
    margin-top: var(--spacing-md);
    box-shadow: var(--shadow-md);
    transition: var(--transition-fast);
}

.primary-btn:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

/* History */
.history-container {
    padding: var(--spacing-xl);
    max-width: 800px;
    margin: 0 auto;
}

#history-list {
    list-style: none;
    position: relative;
    padding-left: 40px;
}

#history-list::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 2px;
    background: linear-gradient(to bottom, var(--color-forest), transparent);
}

.history-item {
    margin-bottom: var(--spacing-xl);
    position: relative;
    background: var(--color-white);
    padding: var(--spacing-md);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-sm);
}

body.dark-mode .history-item {
    background: var(--color-sea-light);
}

.history-item::before {
    content: '';
    position: absolute;
    left: -45px;
    top: 50%;
    transform: translateY(-50%);
    width: 12px;
    height: 12px;
    background: var(--color-forest);
    border-radius: 50%;
    border: 4px solid var(--color-bg-light);
}

body.dark-mode .history-item::before {
    border-color: var(--color-bg-dark);
}